The present invention concerns the sealing of vessels by means of a device ensuring a vent.
This invention concerns more particularly a sealing device for vessels which, when suitably positioned on the vessel to be sealed, makes it possible to avoid practically any leakage of liquid of solid materials from the vessel and also to ensure the automatic elimination of the overpressurized gases existing or formed in this same vessel.
The invention is not limited to a particular type of vessel or container or to a particular field. However, it is easiest to describe the invention and to compare it with the previous technique, by reference to a particular application such as a flask type container having a threaded neck and screwed stopper. It is clear that, as the invention does not apply to this application only, the description which follows may be transposed mutatis mutandis to other categories of containers and/or to other applications, without falling outside the scope of the invention claimed.
The invention is exemplified by the sealing of flasks which contain a cleaning product containing a hypochlorite, in particular a sodium hypochlorite having a high chlorometric degree. It is known that liquid cleaning compounds which contain hypochlorite having a high chlorimetric degree liberate gaseous oxygen during storage through the slow decomposition of the hypochlorite. If the container containing such compounds has a seal which is impervious to gases, an overpressure inside the container resulting from gas generation may take the container swell and leak.
At present, sealing systems are known which provide a valve effect, the triggering of which is automatic, starting from a more or less predetermined overpressure of gas inside the container. These systems operate through displacement by deforming a circular tightness producing part. This displacement is provided by an appropriate profile of the bottom of the plug into which this circular part is inserted. Such sealing systems have the following disadvantages:
(1) They allow not only the gas to escape from the container, but also a mixture of liquid and gas in the form of a foam which oozes and forms crystallized deposits around the sealing system.
(2) In addition, they can operate only if the tightness on the threaded neck of the container remains sufficiently loose to allow a degree of freedom of the circular tightness-producing part to subsist. The sealing system must not be too loose however, or else the liquids can leak from the container.
An unexpected solution to these problems has now been found. Other advantages are described below which are obtained by means of a simple and practical sealing device provided with a vent.
The object of the invention is a sealing device which forms a valve for the automatic elimination of overpressurized gases in a container fitted with such a device. Under normal conditions of use, this device allows practically no liquid or solid materials to leak and does not require adjustment at an incomplete stage of tightening.